thyroid dyshormonogenesis 6

Thyroid dyshormonogenesis, also known as thyroid hormone synthesis defect, is a rare genetic disorder that affects the production of thyroid hormones in the body.

• Causes: This condition occurs due to mutations in one or more genes involved in the synthesis and secretion of thyroid hormones. [6]
• Genetic variants: The most common cause of thyroid dyshormonogenesis is a homozygous or compound heterozygous mutation in the sodium-iodide symporter (NIS) gene, also known as SLC5A5. [6]
• Symptoms: Patients with thyroid dyshormonogenesis may experience symptoms such as hypothyroidism, goiter, and fatigue. [1][2]

Thyroid dyshormonogenesis is a rare condition that affects the production of thyroid hormones in the body. It occurs due to genetic mutations that affect the synthesis and secretion of these hormones.

References: [6] - Thyroid dyshormonogenesis-1 (TDH1) is caused by homozygous or compound heterozygous mutation in the sodium-iodide symporter (NIS) gene (SLC5A5; 601843) on chromosome 16. [6] [1][2] - Patients develop hypothyroidism with a goiter.

Signs and Symptoms of Thyroid Dyshormonogenesis

Thyroid dyshormonogenesis, a rare condition due to genetic defects in the synthesis of thyroid hormones, can manifest in various ways. The signs and symptoms of this condition are often similar to those of other thyroid-related issues.

• Difficulty feeding: Infants with thyroid dyshormonogenesis may experience difficulty feeding, which can lead to poor growth and development.
• Constipation: Affected individuals may also experience constipation due to the reduced production of thyroid hormones.
• Hypothyroidism: The primary symptom of thyroid dyshormonogenesis is hypothyroidism, characterized by a deficiency in thyroid hormone production.

If left untreated, congenital hypothyroidism can lead to more severe complications, including:

• Intellectual disability: Untreated thyroid dyshormonogenesis can result in intellectual disability and slow growth.
• Delayed puberty: Affected individuals may experience delayed puberty or other related symptoms.

It's essential to note that the signs and symptoms of thyroid dyshormonogenesis can be similar to those of other medical conditions, making diagnosis challenging. A proper evaluation by a healthcare professional is necessary for accurate diagnosis and treatment.

References:

• [4] Thyroid dyshormonogenesis is a rare condition due to genetic defects in the synthesis of thyroid hormones.
• [6] They may have difficulty feeding and experience constipation.
• [13] Signs and symptoms of congenital hypothyroidism result from the shortage of thyroid hormones. Affected babies may show no features of the condition, although some

Thyroid dyshormonogenesis, also known as congenital hypothyroidism due to thyroid hormone biosynthesis defects, can be diagnosed through various diagnostic tests.

• Thyroid imaging: Thyroid ultrasonography, thyroid scintigraphy, or perchlorate discharge test can be used for etiological diagnosis. In thyroid dyshormonogenesis, thyroid ultrasonography shows eutopic thyroid and depending on the severity of hypothyroidism, the thyroid size may be normal or large [11].
• Thyroid function tests (TFTs): Measurement of TSH, total thyroxine (T4), free T4, and thyroxine-binding globulin (TBG) can help diagnose congenital hypothyroidism due to dyshormonogenesis. These tests are essential for brain development in infancy [15].
• Genetic testing: Genetic testing can help with making the diagnosis and guide genetic counseling. A 22 gene panel that includes assessment of non-coding variants is ideal for patients with a clinical suspicion of congenital hypothyroidism or thyroid dyshormonogenesis [6].

It's worth noting that treatment with levothyroxine (L-T4) should be started immediately after diagnosis without delaying for imaging purposes, as highlighted in recent recommendations [13].

Treatment of Thyroid Dyshormonogenesis

Thyroid dyshormonogenesis, a form of congenital hypothyroidism, requires prompt and effective treatment to ensure proper growth and development in affected individuals. The primary goal of treatment is to replace the deficient thyroid hormones with synthetic alternatives.

• Levothyroxine (T4) therapy: Levothyroxine is the treatment of choice for thyroid dyshormonogenesis. It is a synthetic form of thyroxine, which is essential for normal growth and development. The starting dose is typically 10-15mcg/kg/day, with the goal of raising serum T4 levels above 130 nmol/L (10 ug/dL) as rapidly as possible [2].
• Early treatment: Early initiation of levothyroxine therapy is crucial in minimizing the neuro-psychological abnormalities associated with untreated congenital hypothyroidism. Studies have shown that high-dose levothyroxine therapy at 10 to 15 mcg/kg daily has been effective in correcting thyroid hormone levels and preventing long-term complications [5].
• Genetic counseling: A definitive molecular diagnosis of thyroid dyshormonogenesis allows for genetic counseling, which is essential in predicting the likelihood of recurrence in future generations. This information can also help differentiate between transient and permanent forms of congenital hypothyroidism [14].

Importance of Compliance

Compliance with thyroid hormone treatment is critical in ensuring optimal outcomes. Regular monitoring of serum T4 levels and adjustments to the dosage as needed are essential in maintaining proper thyroid function.

In conclusion, levothyroxine therapy is the primary treatment for thyroid dyshormonogenesis, and early initiation of this therapy is crucial in preventing long-term complications associated with untreated congenital hypothyroidism.

Differential Diagnosis of Thyroid Dyshormonogenesis

Thyroid dyshormonogenesis, also known as thyroid hormone synthesis defects, is a condition where the thyroid gland produces insufficient amounts of thyroid hormones. The differential diagnosis for this condition includes:

• Aplastic or hypoplastic thyroid: This refers to a condition where the thyroid gland is underdeveloped or missing altogether [7].
• Autoimmune thyroiditis: In this case, the immune system attacks the thyroid gland, leading to inflammation and reduced function [7].
• TSH insensitivity: This is a rare condition where the body's cells are resistant to the effects of Thyroid-Stimulating Hormone (TSH), making it difficult for the thyroid gland to produce sufficient hormones [6].

These conditions can all lead to symptoms similar to those experienced by individuals with thyroid dyshormonogenesis, such as goiter (enlargement of the thyroid gland) and hypothyroidism.

References:

• [7] Clinically the differential diagnosis for congenital hypothyroidism includes aplastic or hypoplastic thyroid and autoimmune thyroiditis. In this case, although ...
• [6] Jun 29, 2015 — Differential Diagnosis List. Congenital hypothyroidism due to thyroid dyshormonogenesis. TSH insensitivity. Fetal iodine syndrome. Final ...